1. Field of the Invention
The present invention relates generally to test handlers for testing semiconductor devices, and more particularly to a semiconductor device loading apparatus for test handlers that is used to precisely transfer semiconductor devices loaded in a presizing unit to the test pockets of a test tray, respectively.
2. Description of the Prior Art
In general, test handlers for semiconductor devices are apparatuses for testing semiconductor devices (hereinafter, referred to as devices) fabricated through a predetermined fabrication procedure, classifying the devices into a plurality of types according to their grades of quality and stacking them according to their grades of quality.
The tester handler functioning as described above is provided with a semiconductor loading apparatus for vacuum-sucking a plurality of devices from a presizing unit and loading the devices in a test tray. The applicant of the present application filed a patent application (Korean Pat. Appln. No. 10-1997-0012445) entitled “a test handler for semiconductor devices with a semiconductor device loading apparatus” and this patent application was issued as Korean Pat. No. 10-0243049.
FIGS. 1 and 2 illustrate a conventional semiconductor device loading apparatus (hereinafter, referred to as “device loading apparatus”) disclosed in Korean Pat. No 10-0243049. As shown in the drawings, the conventional device loading apparatus 100 is constructed to be moved along X and Y-axes by a guider 103, which is movable along a guide rail 102 attached to an X-axis support 101, and a connecting member 106.
The connecting member 106 is provided on its lower portion with a frame member 104 and an elevation cylinder 107 for moving the frame member 104.
The frame member 104 is provided on its lower portion with a pin-fixing plate 130 having a plurality of guide pins 131, which can be inserted into a plurality of pin holes 110d (see FIG. 3) so that pickup cylinders 112 and vacuum adsorbers 111 are located at positions over the corresponding pockets 110a of the test tray 110.
The tops of the pickup cylinders 112 are connected to a zigzag extension member 121 that is operated by an expandable cylinder 122.
FIG. 3 is a plan view showing the construction of the test tray 110 that is loaded with the devices 109 vacuum-sucked by the conventional device loading apparatus 100. As illustrated in this drawing, the test tray 110 is comprised of a plurality of pockets 110a formed to allow the devices 109 to be laid down therein and a frame 110b formed to allow the pockets 110a to be attached thereto in a plurality of rows and columns. The pockets 110a are loosely attached to the surface of the frame 110b to be slightly movable laterally. A plurality of pin holes 110d are formed on the front and rear edges of each pocket 110a to receive the corresponding guide pins 110d of the device loading apparatus 100 so as to guide each device 109 to the pocket 110a when the devices 109 are loaded in the pockets 110a. A device seat 110c formed on the bottom of each pocket 110a has the same size as each device 109.
The device loading apparatus 100 carries out the operation of accurately positioning the devices to be tested in the pockets 110a of the test tray 110. The operation of the device loading apparatus 100 is described in detail with reference to FIG. 4.
First of all, the device loading apparatus 100 is moved to a position over the test tray 110 with the devices 109 being vacuum-sucked by the vacuum adsorbers 111 of the device loading apparatus 100. Thereafter, the device loading apparatus 100 is lowered to approach the test tray 110, and a plurality of guide pins 131 arranged on the bottom of the device loading apparatus 100 are inserted into the pin holes 110d formed in the pockets 110a of the test tray 110. In such a case, when sucking force is removed from the vacuum adsorbers 111 by the pickup cylinder 112, the device 109 is separated from the vacuum adsorbers 111 and positioned in the pocket 110a of the test tray 110.
As described above, the conventional device loading apparatus has a complicated structure and a heavy weight and carries out its operations while being moved vertically and horizontally, so it is difficult to rapidly move the conventional device loading apparatus to an exact position.
In summary, in the conventional device loading apparatus, there are provided the guider 103 movable along an X-axis, the connecting member 106 connected to the guider 103 and the frame member 104 connected to the connecting member 106. In addition, the frame member 104 is provided with the elevation cylinder 107 for moving the device loading apparatus along an Y-axis, a plurality of pickup cylinders 112 provided with a plurality of vacuum adsorbers 111 to load the devices 109 in the test tray 110, the extension member 121 comprised of a plurality of links to adjust the spaces between the pickup cylinders 112 and the guide pin-fixing plate 130 with a plurality of guide pins 131 to accurately position the devices 109 in the pockets 110a of the test tray 110, so the weight of the device loading apparatus 100 is excessive heavy. It is very difficult for the heavy device loading apparatus 100 to rapidly and accurately carry out the operations of picking up the devices 109 and loading them in the pockets 110a of the test tray 110.
Additionally, the conventional device loading apparatus 100 may not accurately position the devices 109 adhered to the vacuum adsorbers 111 in the pockets 110a of the test tray 110 by the guide pins 131.
That is, in the conventional device loading apparatus 100, though the devices 109 adhered to the vacuum adsorbers 111 are loaded in the pockets 110a of the test tray 110 after the guide pins 131 attached to the guide pin-fixing plate 130 are inserted into the pin holes 110d formed in the test tray 110, the devices 109 are not accurately positioned in the pockets 110a but are offset because the falling of the devices 109 to the pockets 110a is carried out without any guidance.
The devices inaccurately positioned in the pockets 110a hinder accurate testing by a test handler, and increase their defective rate.